Newspaper Market Structure and Behavior: Partisan Coverage of Political Scandals in the United States from 1870 to 1910

We study the effect of competition on media bias in the context of US newspapers in the period 1870-1910. We measure bias as the intensity with which different newspapers cover scandals. Using automatic keyword-based searches, we collected data on 121 scandals and 159 newspapers. We also collected data on the partisanship, frequency of publication, and circulation of the newspapers in our sample, as well as of the newspapers circulating in the same cities or towns as those in our sample. Our results indicate that partisan newspapers cover scandals involving the opposition party's politicians more intensely and cover scandals involving their own party's politicians more lightly. More importantly, we find evidence that competition decreases the degree of media bias. The point estimates suggest that compared to a newspaper in a monopoly position, a newspaper facing two competitors will on average exhibit only 50% as much overall bias in coverage intensity.